Simple clinical predictors of stroke outcome based on National Institutes of Health Stroke Scale score during 1-h recombinant tissue-type plasminogen activator infusion

Semantic Visualization in Functional Recovery Prediction of Intravenous Thrombolysis following Acute Ischemic Stroke in Patients by Using Biostatistics: An Exploratory Study

(1) Background: Intravenous thrombolysis following acute ischemic stroke (AIS) can reduce disability and increase the survival rate. We designed a functional recovery analysis by using semantic visualization to predict the recovery probability in AIS patients receiving intravenous thrombolysis; (2) Methods: We enrolled 131 AIS patients undergoing intravenous thrombolysis from 2011 to 2015 at the Medical Center in northern Taiwan. An additional 54 AIS patients were enrolled from another community hospital. A modified Rankin Score ≤2 after 3 months of follow-up was defined as favorable recovery. We used multivariable logistic regression with forward selection to construct a nomogram; (3) Results: The model included age and the National Institutes of Health Stroke Scale (NIHSS) score as immediate pretreatment parameters. A 5.23% increase in the functional recovery probability occurred for every 1-year reduction in age, and a 13.57% increase in the functional recovery probability occurred for every NIHSS score reduction. The sensitivity, specificity, and accuracy of the model in the validation dataset were 71.79%, 86.67%, and 75.93%, respectively, and the area under the receiver operating characteristic curve (AUC) was 0.867; (4) Conclusions: Semantic visualization-based functional recovery prediction models may help physicians assess the recovery probability before patients undergo emergency intravenous thrombolysis.

Factors associated with early improvement after intravenous thrombolytic treatment in acute ischemic stroke

OBJECTIVE

: The aim of this study was to determine the factors associated with early neurological improvement (ENI) in patients who experienced acute ischemic stroke and were treated with intravenous recombinant tissue plasminogen activator (IV rt-PA), and determine the relationship with the outcome at the first control.

METHOD

: This study included 377 patients who were treated with IV rt-PA in Izmir Dokuz Eylül University Hospital between January 2010 and October 2018. ENI was defined as a 4 or more improvement in the National Institutes of Health Stroke Scale (NIHSS) score in the first hour, the twenty-fourth hour and the seventh day when compared to the pretreatment phase. The modified Rankin Scale (mRS) 0-1 score was defined as 'very good outcome'.

RESULTS

: The basal NIHSS (p=0.003, p=0.003, p=0.022) was high in the first hour, twenty-fourth hour, and seventh day ENI groups. Blood urea nitrogen (BUN) level was low in the first- and twenty-fourth-hour ENI groups (p=0.007, p=0.020). Furthermore, admission glucose was low at the twenty-fourth hour and on the seventh day ENI groups (p=0.005, p=0.048). A high infarct volume was observed on magnetic resonance imaging (MRI) at the twenty-fourth hour and on the seventh day non-ENI groups (p= <0.001, p= <0.001).

CONCLUSION

: Management of factors associated with ENI and determination of treatment strategies accordingly are important for obtaining a better clinical outcome. It can help quickly select patients, who, even though they will not respond to rt-PA, may be appropriate candidates for bridging therapy.

Time-dependence of NIHSS in predicting functional outcome of patients with acute ischemic stroke treated with intravenous thrombolysis

OBJECTIVES

The National Institute of Health Stroke Scale (NIHSS) is a predictor for the prognosis of acute ischaemic stroke (AIS) and its prediction is time-dependent. We examined the performance of NIHSS at different timepoints in predicting functional outcome of patients with thrombolysed AIS.

METHODS

This prospective study included 269 patients with AIS treated with recombinant tissue plasminogen activator (rt-PA). Unfavourable functional outcome was defined as modified Rankin Scale score 4-6 at 3 months after rt-PA treatment. Receiver operating characteristic curves were used to examine the predictive power of NIHSS score at admission and 2 hours/24 hours/7 days/10 days after rt-PA treatment. Youden's index was used to select the threshold of NIHSS score. Logistic regression was used to estimate the ORs of unfavourable functional outcome for patients with NIHSS score higher than the selected thresholds.

RESULTS

The threshold of NIHSS score at admission was 12 (sensitivity: 0.51, specificity: 0.84) with an acceptable predictive power (area under curve [AUC] 0.74) for unfavourable functional outcome. The threshold changed to 5 at 24 hours after rt-PA treatment (sensitivity: 0.83, specificity: 0.65) and remained unchanged afterwards. The predictive power and sensitivity sequentially increased over time and peaked at 10 days after rt-PA treatment (AUC 0.92, sensitivity: 0.85, specificity: 0.80). NIHSS scores higher than the thresholds were associated with elevated risk of unfavourable functional outcome at all timepoints (all p<0.001).

CONCLUSIONS

NIHSS is time-dependent in predicting AIS prognosis with increasing predictive power over time. Since patients whose NIHSS score ≥ 12 are likely to have unfavourable functional outcome with rt-PA treatment only, mechanical thrombectomy should be largely taken into consideration for these patients.

Factors Associated with Early Recovery after Intravenous Thrombolytic Therapy in Acute Ischemic Stroke

Introduction

In this study, we aimed to identify the factors associated with early neurological improvement (ENI) in acute stroke patients treated with intravenous recombinant tissue plasminogen activator (IV rt-PA), and to determine the association between ENI and outcomes at 3 months after stroke.

Methods

Patients with acute ischemic stroke who were treated with IV rt-PA within 4.5 hours of symptom onset from February 2009 to December 2016 were included in the study at the stroke center of Eskişehir Osmangazi University Medical Faculty. ENI was defined as an improvement in National Institutes of Health Stroke Scale (NIHSS) score of ≥8 points compared to the pretreatment score or an NIHSS score of 0 or 1 at 24 hours after stroke. We assessed the outcomes at 3 months after treatment using the modified Rankin Scale (mRS) score, and mRS scores of 0-1 were defined as 'very good' outcomes.

Results

ENI was observed in 43.9% of 355 patients included in the study. Very good outcome at the 3rd month was detected in 80.1% of the patients with ENI, and in 15.6% of the patients without ENI (p<0.001). Patients with ENI were younger (p=0.025), and had lower NIHSS scores (p=0.027) and higher ASPECT scores (p=0.008) than those without. The ENI group had lower serum glucose levels at the time of admission (p< 0.001). Additionally, the presence of diabetes mellitus, hypertension, and hyperdense artery sign were more frequent in the ENI group (p=0.001, p=0.024, and p<0.001, respectively). Finally, multiple regression analysis showed a significant relationship between serum glucose level, hyperdense artery sign, and ENI.

Conclusion

There is a significant relationship between ENI and very good outcome at 3 months in acute stroke patients who received IV rt-PA. Therefore, the management of factors such as serum glucose level, NIHSS score, ASPECT score and presence of hyperdense artery sign which are related to ENI, and the determination of treatment strategies according to them are important issues for achieving a better outcome in acute ischemic stroke.

Threshold for NIH Stroke Scale in Predicting Vessel Occlusion and Functional Outcome after Stroke Thrombolysis

Background

Data are limited on optimal threshold for baseline National Institutes of Health Stroke Scale in predicting outcome after stroke thrombolysis (intravenous thrombolysis). Aims Finding thresholds for baseline National Institutes of Health Stroke Scale scores that predict functional outcome and baseline vessel occlusion.

Methods

We analyzed 44 331 patients with available modified Rankin Scale score at three-months and 11 632 patients with computed tomography/magnetic resonance angiography documented vessel occlusion at baseline in the SITS-International Stroke Thrombolysis Register. Main outcomes were functional independency (modified Rankin Scale 0–2) at three-months and baseline vessel occlusion. We obtained area under the curves by receiver operating characteristic analysis and calculated multivariately adjusted odds ratio for the outcomes of interest based on baseline National Institutes of Health Stroke Scale scores.

Results

For functional independency, National Institutes of Health Stroke Scale scores of 12 (area under the curve 0·775) and for baseline vessel occlusion, scores of 11 (area under the curve 0·678) were optimal threshold values. For functional independency, adjusted odds ratio decreased to 0·07 (95% CI 0·05–0·11), and for presence of baseline occlusion, aOR increased to 3·28 (95% CI 3·04–3·58) for National Institutes of Health Stroke Scale scores 12 and 11, respectively, compared with National Institutes of Health Stroke Scale score 0. National Institutes of Health Stroke Scale thresholds decreased with time from stroke onset to imaging, with 2–3 points, respectively, if time to imaging exceeded three-hours.

Conclusions

Ideally, all acute stroke patients should have immediate access to multimodal imaging. In reality these services are limited. Baseline National Institutes of Health Stroke Scale scores of 11 and 12 were identified as markers of baseline vessel occlusion and functional independency after intravenous thrombolysis, respectively. These values are time dependent; therefore, a threshold of National Institutes of Health Stroke Scale 9 or 10 points may be considered in the prehospital selection of patients for immediate transfer to centers with multimodal imaging and availability of highly specialized treatments.

Collateral flow as causative of good outcomes in endovascular stroke therapy

BACKGROUND

Endovascular reperfusion techniques are a promising intervention for acute ischemic stroke (AIS). Prior studies have identified markers of initial injury (arrival NIH stroke scale (NIHSS) or infarct volume) as predictive of outcome after these procedures. We sought to define the role of collateral flow at the time of presentation in determining the extent of initial ischemic injury and its influence on final outcome.

METHODS

Demographic, clinical, laboratory, and radiographic data were prospectively collected on a consecutive cohort of patients who received endovascular therapy for acute cerebral ischemia at a single tertiary referral center from September 2004 to August 2010.

RESULTS

Higher collateral grade as assessed by the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) grading scheme on angiography at the time of presentation was associated with improved reperfusion rates after endovascular intervention, decreased post-procedural hemorrhage, smaller infarcts on presentation and discharge, as well as improved neurological function on arrival to the hospital, discharge, and 90 days later. Patients matched by vessel occlusion, age, and time of onset demonstrated smaller strokes on presentation and better functional and radiographic outcome if found to have superior collateral flow. In multivariate analysis, lower collateral grade independently predicted higher NIHSS on arrival.

CONCLUSIONS

Improved collateral flow in patients with AIS undergoing endovascular therapy was associated with improved radiographic and clinical outcomes. Independent of age, vessel occlusion and time, in patients with comparable ischemic burdens, changes in collateral grade alone led to significant differences in initial stroke severity as well as ultimate clinical outcome.